Despite having a smaller battery capacity, the new iPhone 6s and iPhone 6s Plus achieve the same battery life as their predecessors, the iPhone 6 and iPhone 6 Plus. PhoneArena spotted a scene in Apple’s promotional video showing a 1,715 mAh lithium-ion battery, a reduction from the 1,810 mAh package inside the iPhone 6.

But as per Apple’s Tech Specs webpage, the iPhone 6s provides the same ten hours of 3G or 4G data use, eleven hours of video playback and fourteen hours of talk time on 3G as its predecessor, the iPhone 6.

Here’s that scene.

And here’s the iPhone 6s promotional video that I set to start at mark 2:48, just before the camera shows off the interior of the device.

https://youtu.be/cSTEB8cdQwo?t=2m48s

If you don’t see the video embed, watch it on YouTube.

The following screenshot was taken from Apple’s Compare iPhone Models webpage. You can clearly see that Apple rates the latest iPhones as having the same battery life as their predecessors.

The same run time with a smaller battery capacity is achievable with increased optimization. For example, there are fewer chips on the logic board and the new A9 microchip is more power efficient because it uses smaller transistors that consume less energy.

Besides, it’s not that a difference of 95 mAh makes a major impact, it’s close to negligible. The company may have been forced to use a smaller battery due to a thicker display assembly that accommodates force sensors for features like 3D Display and Taptic Engine.

To be precise, Apple’s battery endurance figures rate both the new iPhone 6s and the previous-generation iPhone 6 as having up to 14 hours of talk time over 3G, 10 hours of browsing on LTE, 11 hours of HD video playback, 50 hours of audio and up to 10 days on standby.

The iPhone 6s Plus is rumored to use a 2,750 mAh battery versus a 2,910 mAh battery inside its predecessor, the iPhone 6 Plus.

The iPhone 6s Plus is officially rated by Apple as providing 24 hours of talk time and 12 hours of browsing—again, the same as the previous-generation iPhone 6 Plus.

Following yesterday’s ‘Hey Siri’ event, Sony took to social media to publicly ridicule the iPhone 6s battery life, saying its latest Xperia Z5 smartphone offers up to two days of run time on a single charge.